Design of Rotman lens for 5G wireless applications at 24 GHz

In this study, we present the design of beamforming using the Rotman lens (RL) structure for 5 G wireless applications. The Rotman lens is microstrip-printed on a Rogers RO3003 substrate. It is composed of five beam ports and seven output ports, operating in the 24 GHz frequency band. Height dummy ports are added to reduce multiple reflections and standing waves, which can degrade lens performance. This method greatly minimizes mutual coupling between the ports and enhances antenna performance by suggesting the use of absorbent material on these dummy ports in place of equivalent charges. Matlab and CST Microwave Studio are used to model the RL structure. The design has demonstrated outstanding performance in terms of S-parameters, VSWR, return loss, and mutual coupling between ports across a broad bandwidth ranging from 20 GHz to 26 GHz. Results are compared with previously published data and are found to be in good agreement.